Reporting from Mexico City — Shackled in chains, he grimaced in apparent pain as he heaved his hefty body from the back of a police van. Jose de Jesus "El Chango" Mendez was paraded before reporters Wednesday, a day after the reputed drug lord was captured by federal police.

Authorities identify Mendez as the reigning leader of the notorious La Familia cartel, and his capture — with nary a shot fired, officials say — is a coup for the besieged government of President Felipe Calderon, whose drug war has claimed nearly 40,000 lives in 4 1/2 years.

But will the removal of Mendez destroy La Familia, the largest supplier of methamphetamine to the United States? And, more important for Mexicans, will it lessen the deadly violence gripping this country and eroding its institutions?

If past experience is any indication, the answer in both cases is probably no.

"The government always thinks, kill the dog, you kill the rabies," said Jose Reveles, author of several books on Mexico's drug war. "If La Familia disappears, it will be from its own divisions."

Mendez, whose nom de guerre means "the monkey," allegedly moved into the top slot at La Familia after its founder, the Bible-thumping, messianic Nazario Moreno Gonzalez, was killed by security forces in a major offensive in December. After that, the group began to splinter, but it did not halt its operations.

Facundo Rosas, general commissioner of the federal police, said Wednesday that Mendez recently took refuge in the relatively placid state of Aguascalientes, with both government troops and, perhaps more crucially, enemy drug gangsters in hot pursuit. It was there that he was found Tuesday, surrounded by bodyguards but unable to put up resistance.

A law enforcement operation May 27-28, in which authorities killed 15 members of Mendez's cartel and captured 39, yielded actionable intelligence on the capo's movements, Rosas said. In the past, gangs have often tipped authorities to their rivals' whereabouts.

"He had begun looking for where to protect himself. The authorities were closing in, and his adversaries were also searching for him to do him serious damage," Rosas said. "With this, La Familia is totally weakened and effectively taken apart."

Government security affairs spokesman Alejandro Poire said La Familia had suffered "the biggest blow in its history."

When cartel founder Moreno was killed two weeks before Christmas, officials at the time used nearly identical language to proclaim victory over La Familia, an often cultlike and vicious gang based in Calderon's home state of Michoacan.

Yet the bloodletting only intensified as Mendez allegedly battled another Familia leader, Servando "La Tuta" Gomez Martinez, for control. Police say Gomez formed his own faction, bizarrely named the Knights Templar, and in March festooned cities in Michoacan with banners and fliers announcing it was taking over.

This month alone, the bodies of nearly 50 people — 20 corpses around June 8 and 26 last weekend — turned up in spots throughout Michoacan as part of that fight, authorities say.

It is a familiar pattern. Removing the top capos, which is Calderon's stated strategy, provokes violent power struggles as potential successors compete for their share of the ever-lucrative drug trade. Such was the case after the killing by Mexican marines of Arturo Beltran Leyva, chief of another, older cartel, in December 2009.

With presidential elections set for next year, the Calderon government has come under severe pressure as the death toll mounts and the public demands better security. The president and his aides defend their strategy, saying it is bearing fruit but will require time to reduce violence.

"The detention of the most dangerous heads of organized crime is indispensable for weakening" the cartels, Poire said. "We are convinced this is the right way to restore the peace and security desired by everyone."

Thanks in large part to intelligence from U.S. agencies, Mexican authorities have carried out damaging strikes against several cartels.

Mendez, Moreno and Beltran Leyva are three of at least eight suspected senior cartel leaders who have been killed or caught in the last year and a half.

Critics argue, however, that in addition to the wider violence that those actions generate, at least temporarily, Calderon's drug war is seriously flawed by its failure to follow through with effective prosecutions, the pursuit of drug money and the eradication of drug-financed corruption. Cartels exert control over entire chunks of territory in such states as Michoacan, as well as in Tamaulipas, Durango and Chihuahua, and the removal of top bosses does not seem to have changed that dynamic.

La Familia has proved an especially vexing cartel, one that prospered and grew into one of the country's most dangerous in just the last few years. It first gained national attention by tossing five severed heads onto the floor of a dance hall in September 2006. Three months later, Calderon sent troops into Michoacan for the first time to take on traffickers.

La Familia has diversified beyond its flourishing meth trade to activities including counterfeiting, extortion and kidnapping. In Michoacan, it infiltrated police ranks and city halls while spreading into neighboring Guerrero and Mexico states, as well as at least 30 U.S. towns and cities, including the Los Angeles area.

Federal authorities attempted to crack La Familia's hold on Michoacan by arresting 35 mayors, police commanders and other state officials in 2009, alleging they were on the traffickers' payroll. The entire case fell apart, and all of those arrested have been freed.